This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Professor Mariuzza is interested in an extracellular matrix protein called mindin. Mindin was recently shown to be an LPS- binding protein as well as an integrin ligand. The X-ray structure of mindin was previously determined and its integrin binding site has been mapped by mutational analysis. There are two forms of mindin. The recombinant protein, which is produced by bacteria does not bind to LPS. In contrast, the mindin produced in mammalian cells (HEK 293), has both integrin- and LPS-binding activities. SDS-PAGE showed that mammalian mindin is modified post-translationally compared with bacterial mindin. The post-translation modification appears to be required by LPS binding. Mindin has no N-linked glycosylation sites, but potential sites for both O-linked glycosylation and C-mannosylation were present. Dr. Mariuzza was interested in knowing the nature and location of this modification.